The present invention relates to a spring mattress comprising a plurality of interconnected coil-spring elements, and to a method of manufacturing said mattress.
Conventionally, in the manufacture of spring mattresses comprising layers of coil springs arranged between the bed frame and the surface of the mattress, the springs are joined together at the spring ends. Usually springs of the kind known as Bonnell springs are used, wherein neighbouring springs are interconnected in pairs by means of spirals, which are coiled about the adjacent parts of turns in the respective adjacent spring. Thus, the spirals extend in parallel with the surface of the mattress, i.e. across the centre axes of the springs, either in the longitudinal or width direction of the mattress.
This classical mattress does, however, suffer from a number of disadvantages. Since the spirals lock turns in neighbouring springs together rather firmly, the springs fail to be individually resilient. As a result, load on one of the springs of the mattress will cause deflection not only of that spring but also of neighbouring springs. This is a disadvantage, as it detracts from the adaptability of the mattress and because the latter will not distribute the supporting force evenly across the user""s entire body surface, and in consequence the mattress is felt as being less comfortable.
In addition, the spirals are wound from metal wire resulting not only in the need for a comparatively complex assembly method but also in a stiff mattress surface that may be felt as bumpy.
Consequently, one object of the present invention is to provide a spring mattress of the kind defined in the introduction but wherein the disadvantages from which prior-art mattresses of this kind suffer have been completely or at least partly eliminated.
This object is achieved in a spring mattress and by means of a method of manufacturing said mattress in accordance with the present invention.